Crowfoot (c. 1830 – 25 April1890) or Isapo-Muxika (BlackfootIssapóómahksika, "Crow-big-foot) was a chief of the SiksikaFirst Nation. His parents, Istowun-eh'pata (Packs a Knife) and Axkahp-say-pi (Attacked Towards Home), were Kainai. His brother Iron Shield became Chief Bull. He was only five when Istowun-eh'pata was killed during a raid on the Crow tribe, and a year later, his mother remarried to Akay-nehka-simi (Many Names) of the Siksika people. The young boy was adopted by the Siksika, who gave him the name Kyi-i-staah (Bear Ghost), until he could receive his father’s name, Istowun-eh’pata.

While a young man, he was included in horse raid on a Crow encampment. Because of his brave performance and injury during the battle, he was finally given his adult name, Isapo-muxika, taken from a deceased relative.

Crowfoot was a warrior who fought in as many as nineteen battles and sustained many injuries. Despite this, he tried to obtain peace instead of tribal warfare. When the Canadian Pacific Railway sought to build their mainline through Blackfoot territory, negotiations with Father Lacombe convinced Crowfoot that it should be allowed.